The present invention is directed, in general, to a mounting bracket for an equipment rack, and, more specifically, to a mounting bracket to securely mount heavy electronics equipment to the columns of an equipment rack.
Earthquakes, floods, hurricanes and other natural catastrophes are aggravated by confusion and lack of information. One system heavily relied on by victims of such catastrophes is the public telephone system. If the public telephone system is working, disaster relief efforts can be coordinated and people involved in the disaster can seek assistance and be kept informed. Regulatory authorities and consumers both expect the public telephone system to survive natural catastrophes, or at least to be among the first systems to be put back into service.
The survivability of a telephone system is, among other things, dependant on the survivability of locations housing the electronics equipment that forms the heart of the system. The equipment at such locations must remain operational for the telephone system to remain serviceable.
Electronics equipment used in the telecommunications industry is typically configured as a number of electronic modules, each of which is housed in a case or chassis, that combine to make up the overall system. These modules are mounted to equipment racks that, to the casual observer, have the appearance of a large number of closely packed drawers with only the faces of the modules being visible. A typical prior art equipment rack has a pair of columns, which may be C-shaped vertical channels, between which a number of electronic equipment chassis are mounted, one above the other. Unless the rack can withstand the ravages of a natural disaster, such as an earthquake, and retain the equipment mounted thereon, the telephone system risks being rendered inoperable.
For this reason, a number of regulatory agencies require the use of rack mounting systems capable of withstanding prescribed vibration levels approximating that of an earthquake. In the majority of equipment racks now in use, each electronic equipment chassis is mounted to the rack by using two xe2x80x9cearxe2x80x9d brackets, one fastened to each side of the chassis. The other end of each xe2x80x9cearxe2x80x9d bracket is attached to one flange of the column by one or more bolts or screws. This type of equipment rack requires the mounting brackets to be located on or near the balance point (center of gravity) of the chassis. Lighter pieces of electronics equipment mounted in this manner generally meet most requirements regarding earthquake survivability. However, heavier pieces of equipment with an xe2x80x9cearxe2x80x9d bracket attached to the chassis at the chassis balance point and fastened to a single flange of an equipment rack frequently will not meet earthquake survivability requirements.
Additional factors, besides earthquake survivability, must also be considered in selecting the right rack to mount electronics equipment. Because the electronic equipment chassis must be removable for maintenance purposes or to upgrade the electronics inside, easy removal and ready access are prerequisites. Space considerations for the equipment must also be considered. For these reasons most equipment racks are only accessible from the front and the electronics equipment is mounted so close together that one chassis abuts, or nearly abuts, the adjacent chassis.
Prior art solutions satisfying earthquake survivability requirements have included locating the electronics equipment on shelving supported by brackets that provide additional support. Shelving and brackets, however, takes up space that could otherwise be devoted to more electronic equipment. The shelving also increases the weight of the equipment rack and may block airflow inside the equipment rack. Another prior art solution called for the use of a double-sided mount with screw fasteners attached to each flange of the column. This, however, required access to both sides of the mounting rack. In addition, most prior art equipment racks only have mounting holes on the front side of the rack.
Another prior art solution is to use a four channel rack mounting system. A four channel rack has two vertical C-channel racks adjacent to one another on each side of the rack between which the equipment is mounted. While such an equipment rack will readily withstand about any earthquake testing, the problem of access to both sides of the rack remains.
Therefore, what is needed in the art is a chassis mount that can be attached to an electronic equipment chassis for mounting the chassis in an equipment rack where the chassis is supported by two surfaces, but does not require access to both sides of the rack in order to install the chassis.
To address the above-discussed deficiencies of the prior art, the present invention provides a chassis mount for mounting an electronic equipment chassis to a rack that has parallel mounting columns with opposing front and rear flanges. The chassis mount has front brackets that are fixedly attached to the electronic equipment chassis and positively engageable with the front flanges of the mounting columns. The chassis mount also has rear brackets movably attached to the electronic equipment chassis and locatable proximate to the rear flanges of the mounting columns. A binding mechanism is coupled to the front and rear brackets to form a clamp therewith that binds the columns between the front and rear brackets and secures the electronic equipment chassis to the rack.
The present invention therefore broadly introduces a chassis mount that has more than one point of contact to support an electronic equipment chassis in a rack. The mount provides a clamp that can be bear against both mounting columns of a rack without requiring physical access to both flanges of the mounting columns. This mount is particularly advantageous, because it permits a heavy electronic equipment chassis to be mounted without the requirement that the chassis be centered in the rack. The chassis may thus be mounted at its center of gravity, or in any position with respect thereto. In some equipment mounting applications, it may be necessary to xe2x80x9cflush mountxe2x80x9d the equipment, with the chassis xe2x80x9cflushxe2x80x9d with the front flange of the rack. Increased resistance to the torque resulting from the off-center mounting is, at least partially, counteracted by the two-surface clamping action of the mount.
In one embodiment of the invention the chassis mount has a rack mounting bolt couplable to the front brackets to provide additional support to the chassis. In another embodiment, unthreaded pins couplable to the front brackets are used to provide additional support to the chassis. In an advantageous embodiment, the chassis mount has an adjustment slot in at least one of the front and rear brackets to permit the mount binding mechanism to be adjusted to accommodate columns having various web dimensions. In another embodiment, the chassis mount has adjustment slots in the front and rear brackets to permit the mount binding mechanism to be adjusted to accommodate columns having flanges of varying dimensions.
In still another embodiment, the chassis mount has a bridge on the front brackets to support the rear brackets and hold them in place before the binding mechanism binds them against the rear flanges of the mounting columns. In yet another embodiment of the invention, the mount binding mechanism includes an adjusting screw which engages a nut adjacent the rear brackets for tightening the adjusting screw.
Other embodiments of the invention include methods of manufacturing a chassis mount. In one embodiment, the method comprises forming front brackets to be fixedly attached to the chassis and positively engageable with the front flanges of the mounting columns. Rear brackets are formed such that they are movably attached to the chassis and locatable proximate the rear flanges. A binding mechanism is formed to couple the front and rear brackets together so they form a clamp that can bind the mounting columns between the front and rear brackets.
Yet another aspect of the invention provides an electronic equipment assembly. In one embodiment, the electronic equipment assembly includes an electronic equipment chassis and a rack with parallel mounting columns that have opposing front and rear flanges. The equipment assembly also includes a chassis mount to secure the electronic equipment chassis to the rack.
The foregoing has outlined, rather broadly, preferred and alternative features of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiment as a basis for designing or modifying other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form.